Noritada Matsuo

Preparation of optically active 1-acetoxy-2-aryloxypropionitriles and its application to a facile synthesis of (S)-(−)-propranolol

Abstract (S)-1-acetoxy-2-aryloxypropionitriles were synthesized by an asymmetric hydrolysis of the racemates with an enzyme. (S)-propranolol, a typical β-adrenergic blocker, was synthesized from (S)-1-acetoxy-2-α-naphthyloxypropionitrile in two steps.

Metofluthrin: A Potent New Synthetic Pyrethroid with High Vapor Activity against Mosquitoes

(1R)-trans-Norchrysanthemic acid fluorobenzyl esters are synthesized and their structure-activity relationships are discussed. These esters show outstanding insecticidal activity against mosquitoes. In particular, the 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl analog (metofluthrin) exhibits the highest potency, being approximately forty times as potent as d-allethrin in a mosquito coil formulation when tested against southern house mosquitoes (Culex quinquefasciatus). Metofluthrin also exhibits a significant vapor action at room temperature.

Studies on hydrolysis of chiral, achiral and racemic alcohol esters with Pseudomonas cepacia lipase: mechanism of stereospecificity of the enzyme

Steady-state kinetics of Pseudomonas cepacia lipase-catalysed hydrolysis of five analogous chiral and achiral substrates, i.e. (R)- and (S)-1-methyl-2-(4-phenoxyphenoxy)ethyl acetates (R)- and (S)-1a, (R)- and (S)-2-methyl-2-(4-phenoxyphenoxy)ethyl acetates (R)- and (S)-1b and 2-(4-phenoxyphenoxy)ethyl acetate 1c, were investigated in sufficiently emulsified reaction mixtures of water-insoluble substrates. The apparent Michaelis constant Km values were identical for all the esters, and no nonproductive binding was observed in these substrates. The apparent catalytic constants kcat were found to reflect the leaving abilities of the alcoholate ions for the fast-reacting enantiomers. These observations, based on the findings that acyl-enzyme intermediate formation was rate-determining in the overall reaction, strongly suggested that all the substrates are bound to the enzyme in the same manner whether or not the alcohol moiety has a medium-sized substituent LM at the stereocentre and that the breakdown of a tetrahedral intermediate is rate-determining in the acylation of the enzyme. Time courses were also studied for the hydrolysis of racemic 1-ethyl-2-(4-phenoxyphenoxy)ethyl acetate 1d together with 1a, 1b and 1c. The enzyme distinguished (R)-1d from its antipode perfectly and hydrolysed only the (R)-enantiomer. These results were interpreted to indicate that LM of the slow-reacting enantiomer is positioned close to the imidazole ring of the catalytic His and hinders NIµ2 of the residue from forming a weak interaction with O1 of the leaving alcohol and that the breakdown of the tetrahedral intermediate is thus inhibited.

New Trifluoromethanesulfonanilide Compounds Having High Miticidal Activity against House Dust Mites

Several 2-alkoxycarbonyltrifluoromethanesulfonanilides were prepared to examine their miticidal activity. 4-Halo-2-alkoxycarbonyltrifluoromethanesulfonanilides in particular showed good miticidal activity against Tyrophagus putrescentiae (Tp), Dermatophagoides farinae (Dp) and Chelacaropsis moorei (Cm). Amidoflumet (methyl 5-chloro-2-[(trifluoromethyl)sulfonyl]aminobenzoate) was selected and has been developed as a new miticide for house dust mites.

Synthetic pyrethroids containing a C–C triple bond†

The three commercial synthetic pyrethroids containing a carbon-carbon triple bond, α-ethynyl-2-methylpent-2-enyl (1 R)-trans-chrysanthemate, (S)-2-methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl (1R)-trans,cis-chrysanthemate and [2,5-dioxo-3-(2-propynyl)-1-imidazolidinyl]methyl (1R)-trans-chrysanthemate are reviewed with emphasis on their inventive histories. Their chemistry and efficacy are described briefly. The relationship between stereochemistry and the biological activity is also discussed.

Synthesis of all stereoisomers of the norchrysanthemic acid methyl ester

Abstract Syntheses of eight stereoisomers of methyl norchrysanthemate, (1R)‐trans‐(Z)‐isomer and (1R)‐trans‐(E)‐isomer from (1R)‐trans‐chrysanthemic acid, and other six isomers from (+)‐3‐carene, are described.

CYCLOPROPANEGARBOXYLATE WITH FOUR SUBSTITUENTS ON THE CYCLOPROPANE RING, A POTENT PYRETHROID

Novel spiro-fused cyclopropanecarboxylic acids have been prepared. One of esters derived from these acids and α-cyano-3-phenoxybenzyl alcohol was more active to housefly than fenpropathrin and cypermethrin. Synthesis of these acids and activities of the esters derived from the acids against various insects are presented.

Recent Advances of Pyrethroids for Household Use

Development of pyrethroids for household use and recent advances in the syntheses of (1R)-trans-chrysanthemic acid, the acid moiety of most of the household pyrethroids, are reviewed. As another important acid moiety, we discovered norchrysanthemic acid to have a significant vapor action at room temperature when esterified with fluorobenzyl alcohols. In particular, 2,3,5,6-tetrafluoro-4-methoxymethylbenzyl (1R)-trans-norchrysanthemate (metofluthrin) exhibits the highest potency in mosquito coil formulations as well as the vapor action at room temperature against various mosquitoes. Structure-activity relationships of norchrysanthemic acid esters and synthetic studies of norchrysanthemic acid are discussed.

A Novel Catechol Compound, an Unusual Side Reaction Product of a β-Ketoester with Pyruvic Aldehyde and Its Inhibition by Sodium Dithionite

Abstract The structure of an usual catechol byproduct in the aldol condensation of the salt of 3-oxo-6-heptenoate and pyruvic aldehyde, and the discovery of an additive to inhibit its formation are described.

THE ABSOLUTE STRUCTURE AND ACTIVITY RELATIONSHIPS OF MAJOR SECONDARY ALCOHOLS OF PYRETHROID INSECTICIDES

ABSTRACT Optically active forms of various χ-ethynyl pyrethroid alcohol moieties were newly prepared for determination of their absolute configurations, and the toxicity ratios of the respective (S)-alcohol ester to the (R)-ester to housefly were assessed. As for the acyclic χ-ethynyl alcohol esters, the toxicity ratios were generally high and consistent over available examples. Whereas, the ratios were essentially dependent on both the species and position of a substituent on the benzene ring regarding the χ-ethynylbenzyl analogs. The essential stereochemical requirements for the active ethynyl alcohols were discussed in comparison with other major secondary alcohols as represented by (S)-allethrolone and (S)-χ-cyano-3-phenoxybenzyl alcohol.